Thursday, December 31, 2009

Want to extract some DNA?

It’s so easy you can actually do it at home. Try it like this:

  1. Take some animal or vegetable, like uncooked steak or leaves.
  2. Add some salt water.
  3. Toss it in a blender and liquefy.
  4. Add some dish soap. This dissolves the cell membranes the blender doesn’t.
  5. Then add some meat tenderizer, which breaks down the proteins attached to DNA.
  6. Then add some rubbing alcohol. Do not mix!

By the end, you’ll have a mush on the bottom and clear alcohol on top. Alcohol has a real attraction to DNA, and if you’ve done it right, a lumpy white ball should appear in the alcohol. This is DNA.

Do it yourself!

Monday, December 28, 2009

The Science of Avatar

It’s not often that I recommend a movie for the scientific content, but James Cameron’s “Avatar” is downright mindblowing. “Avatar” is one of the most scientifically literate movies seen in some time. What “Jurassic Park” was to genetics, “Avatar” is to ecology and biology. In addition to the pretty colors and effects, it’s obvious that a lot of work was placed into figuring out the plausibility of the rain forest planet Pandora’s life forms.

You can always expect scientific accuracy from Cameron, who knows his oysters, and proved it, with "The Abyss." I actually first saw that film in high school Marine Biology!

You know, usually I’m irritated by all the tie-in books that accompany a major movie release, but this time, I’d actually be interested in checking them out. It’s obvious that a lot of thought was placed into the scientific verisimilitude of this world ecology, and that one of the limitations of a movie like this one is that we don’t see any of that work, as it is in the background. I’d love to read more about the world and then come back and see the film. I’m sure my appreciation would be improved.

One of the occasions where it was obvious they knew what they were doing was in a sequence where the characters meet a weird carnivorous creature, who goes after a herd of herbivores…but backs off when he sees them in a herd. Only then does he think about attacking our human heroes. This was a startlingly logical set of behaviors! Incidentally, the ratio of herbivores to carnivores is spot-on. Carnivores are rare in any ecosystem, since they require a lot of herbivores to maintain themselves.

Some of the great sky-shots are dominated by a giant Jupiter-like planet in the distance, which leads me to think that Pandora may not be a planet in the traditional sense, but a moon of a gas giant. The idea of Pandora as a moon may be a little unimpressive, but consider that there are moons in our solar system that are near planet-sized. Saturn’s moon Titan, the largest moon in the solar system, is bigger than Mercury and Pluto.

Actually, this makes a great deal of sense of you consider the vast biodiversity of Pandora life. I mean, a single, big planet-killer asteroid and the whole ecosystems would have to start from scratch. But imagine a very close, huge gas giant nearby, with gravity that deflect nearly all objects. Considering how many stellar objects are deflected by earth’s moon and multiply that.

All of the most exhilarating moments of the film are set on winged riding birds, which the Na’Vi, the blue furry space monsters, can actually ride. The idea of birds growing to be that huge…and able to carry 12 foot giant riders…defies the laws of biology at least on earth. There is no more expensive biological process than flight, after all.

But the movie, in a first, actually pays attention to why flight for huge creatures is possible, which surprised me. The atmosphere is far denser than that of Earth's, which means it can provide greater buoyancy. It's also stated that Pandora has a lower gravity, which also reduces the force of drag.

What I find impressive is that most of the reptilian flying creatures have four wings, two for control on the legs. This sounds a little exotic, but it is true that a dinosaur, discovered in China, called microraptor had this very feature!

The script states that Pandora orbits Alpha Centauri A, the second closest visible star to earth that is 4.3 light years away and it takes five years to get there, which means that the ships in this future can travel at around 85% of the speed of light. I know Alpha Centauri gets mentioned a lot in science fiction, but I kind of like that Cameron felt the need to specify Alpha Centauri A, since Alpha Centauri is a double-star (technically a triple if you count Proxima, a brown dwarf), both of which are 23 AUs apart.

All of this is nothing before a science fiction idea that appears near the two-thirds mark that is so original and unexpected and entertaining that, in all honesty, I think revealing it counts as a spoiler. You’ve been warned!

Early on in the film, it is established that the giant natives venerate a type of life-force existing on the planet, which the main character says consists of . They have nerves at the base of their ponytails that let them “plug in” and link up to animals that they ride. That’s cool enough, but what’s interesting is that all the trees on the planet link up to form a gigantic neural computer network. Sigourney Weaver, who plays a brassy female scientist, said that each tree had 104 connections to the trees around it, and there were 1012 trees on the planet, which means this giant biological/chemical computer network has more processing power than the human brain. (This is not only true but an understatement. Each person has 1010 neurons and each has 7,000 connections) This means the entire planet is one giant living computer.

I was expecting some dull, unoriginal idea about life forces and mother goddesses – as unwelcome in a science fiction movie as an abortion in a Disney cartoon. This was actually a great idea.

As for the visual look, it really is everything everybody says it is. Me, a science student, and my friend getting her masters in visual arts, were equally blown away.

As for the film’s creative elements, I have to admit that it was not one of Cameron’s best movies at all, even though it's obvious the movie has a conscience. The biggest problem is that it is predictable. I can see every plot development coming from a mile away. There was one that was especially ridiculous one that goes something like, “only our greatest warriors have ridden the magical orange pterodactyl.” Followed by, “gasp! He has ridden the magical orange pterodactyl!” Still, it’s great to see Sigourney Weaver in anything again. And yes, she has an avatar too, something not a single trailer mentions.

Monday, December 21, 2009

Pluto is NOT a planet

I was startled to see so many people disappointed that Pluto isn’t considered a planet anymore. To anyone that knows much about Pluto, it makes perfect sense. Considering Pluto a planet is like considering Greenland a continent.

Pluto is one of the largest of the trans-Neptunian Kuiper Belt (a second asteroid belt outside the boundaries of the Solar System, over 20 times larger and 200 times more massive than the one between Mars and Jupiter), but is one-fifth the size of our moon. Pluto’s composition of ices means that if Pluto was brought into the inner solar system, it would acquire a tail like a comet and eventually burn off.

What’s even more embarrassing is that another Kuiper Belt object, Eris, was discovered in 2005 that is actually even bigger than Pluto! Pluto isn’t even the biggest of the objects out there! What’s more, they are constantly discovering huge objects on the Kuiper Belt. Most of them have the same general look as Pluto: rocky balls of frozen ices. It’s also commonly believed some moons in the solar system, some many times larger than Pluto, are originally Kuiper Belt objects.

In other words, Pluto isn’t that special, as astronomers are now finding out. Does an object this dubious really deserve the honor of being called a planet, in the same category as Earth and Jupiter?

Lots of people get sentimental about Pluto, but what about poor Ceres? Now there’s a world left off from our childhood nursery rhymes! Ceres, as you might know, is the largest of the asteroids and composes at least a third of the mass in the Mars-Jupiter asteroid belt, a much greater percentage than Pluto has in the Kuiper Belt. Ceres is smaller than Pluto but rock all the way through and is, in many ways, a much better candidate than Pluto for planethood.

The specific definition of what constitutes a planet is a definition that is long overdue – this is one of the many occasions where words mean things, and that definition should be specific as possible. The solar system has a lot of junk in it and not all of it is a planet. In fact, I once heard a great way an alien space probe would define our solar system: the Sun, Jupiter, and some debris!